The object of the invention relates more precisely to technical means suitable for cleaning the wells of such test cards.
The prior art has proposed various devices for cleaning the wells of a test card. For example, U.S. Pat. No. 4,635,665 describes a cleaning device comprising at least one washing head with two coaxial tubes designed to be inserted into the interior of the well to be cleaned to extend in proximity to the bottom of the well. The cleaning head comprises a cleaning tube delivering, at its free end, a cleaning fluid, and a suction tube mounted concentrically within the cleaning tube and designed to aspirate the contaminated cleaning fluid. The adjoining ends of the suction tube and the cleaning tube are situated in one and the same plane to ensure effective aspiration. Injection of the cleaning liquid at the center of the head and the aspiration of the contaminated liquid at the periphery of the head does not make it possible to ensure total recovery of the contaminated liquid.
U.S. Pat. No. 5,882,597 describes a cleaning device comprising a series of cleaning heads each comprising a cleaning tube communicating with a cleaning fluid storage chamber and delivering, at its free end, a cleaning fluid. Each cleaning head also comprises a suction tube for aspirating the contaminated cleaning fluid from its free end, which extends beyond the free end of the cleaning tube. The terminal portion of the cleaning tube is flared to ensure that the liquid leaves in an annular pattern so as to ensure fluid-tightness preventing air from rising into the storage chamber. The cleaning head is displaced so as to enter the interior of the well to be cleaned.
It appears difficult in practice to ensure coaxial mounting of the two tubes, so the proper functioning of such a cleaning head cannot be ensured. Moreover, it has been observed that such a cleaning head does not give satisfaction, inasmuch as it does not allow effective cleaning of the well to be obtained with certainty.
The present invention therefore aims to correct the disadvantages of the prior art by proposing a new technique for cleaning the wells of a diagnostic test card, designed to completely and reproducibly clean the test sample wells of a diagnostic test card.
To attain such a goal, the object of the invention aims to propose a method for cleaning at least one test sample well, provided in a diagnostic test card, using at least one cleaning head comprising at least one cleaning tube delivering, at its free end, a cleaning fluid, and suction tube mounted within the cleaning tube, for aspirating the contaminated cleaning fluid from its free end located in proximity to the free end of the cleaning tube, the method consisting of providing for relative displacement between the test card and the cleaning head so that the test card occupies a cleaning position wherein the cleaning tube delivers the cleaning fluid, at its free end, into the well to be cleaned, and the suction tube aspirates the contaminated cleaning fluid.
According to the invention, the method consists, in the cleaning position, of providing for intake of air between the exterior and the interior of the free end of the cleaning tube so as to create a vortex in the cleaning fluid within the well to be cleaned.
In addition, the method according to the invention can also exhibit, in combination, at least one and/or another of the following additional features:
providing for relative displacement between the test card and the cleaning head so as to ensure abutment of the free end of the cleaning tube on the test card for the purpose of creating the air intake.
equipping the free end of the cleaning tube so that the free end of the cleaning tube creates the air intake when it is in abutment on the test card,
equipping the test card so that said test card creates the air intake when the free end of the cleaning tube is in abutment on the test card,
equipping the free end of the cleaning tube with a flexible tip, which either delimits the air intake or ensures fluid-tightness with the card when said tip is in abutment on the test card,
ensuring abutment of the free end of the cleaning tube on the card for the purpose of creating a suction zone of predetermined height between the free end of the suction tube and the bottom of the well,
creating the suction zone of predetermined height between the free end of the suction tube and the bottom of the well, with the free end of the suction tube extending beyond the free end of the cleaning tube,
creating the suction zone of predetermined height between the free end of the suction tube and the bottom of the well, with the free end of the suction tube extending short of the free end of the cleaning tube,
aspirating the contaminated cleaning fluid at the free end of the suction tube, at several separate suction sections located, in the cleaning position, vertically above spots placed in the test sample well,
providing for relative displacement between the test card and the cleaning head so as to laterally displace the suction zone with a predetermined height between the free end of the suction tube and the bottom of the well when the suction zone does not allow cleaning the bottom of the well in a single position.
Another object of the invention is to propose a cleaning head for at least one test sample well provided in a diagnostic test card, comprising at least one cleaning tube connected to a cleaning fluid source and delivering, at its free end the cleaning fluid, and a suction tube mounted inside the cleaning tube and connected to a suction source and aspirating, at its free end, located in proximity to the free end of the cleaning tube, the contaminated cleaning fluid.
According to the invention, the cleaning tube is provided with an air inlet between the outside and the inside of its free end, in proximity to or on its transverse face.
In addition, the cleaning head according to the invention can also exhibit, in combination, at least one and/or another of the following additional features:
the air intake comprises a series of channels provided on the transverse face delimiting the free end of the cleaning tube, said channels extending radially between the outside wall and the inside wall of the cleaning tube,
the channels are distributed evenly over the transverse face of the cleaning tube,
the cleaning tube has a rough transverse face delimiting the air intake between the outer wall and the inner wall of the cleaning tube,
the free end of the suction tube is located short of the free end of the cleaning tube,
the free end of the suction tube is located short of the free end of the cleaning tube by a value comprised between 10 and 300 μm,
the cleaning tube is provided with a flexible tip forming the free end of said cleaning tube,
the suction tube comprises within it a duct communicating with the suction source and equipped at its free end with partitions delimiting separate suction sections.
Another object of the invention is to propose a cleaning device comprising a cleaning fluid source, a suction source for the contaminated cleaning fluid, at least one cleaning had and a system for relative displacement between the cleaning head and the diagnostic test card wherein is provided at least one test sample well, the displacement system being controlled to occupy at least one well cleaning position.
According to the invention, the device comprises at least one cleaning head, the tube whereof is capable, in the cleaning position, of coming into abutment at its free end on the test card to create an air intake between the outside and the inside of the free end of said cleaning tube.
Various other features are revealed by the description given below with reference to the appended drawings which show, by way of non-limiting examples, embodiments of the object of the invention.